Chuck



Jan. 13, 193.1.

(5. E. GARNO ET AL CHUCK Filed May 25, 1928 u m mm/ w W d m W F q q mu 3 a n neH 7 Geo E Patented Jan. 13, 1931 r is J ma GEORGE GAR-NO AND EUGENE AMENGSTBOIF or woncnsrnn, MASSACHUSETTS, As-

sienons TO TEE nEALn MACHINE} oorarannor won ons'rnn, MA$SACHUSETTS, A

CORPORATION OF MASSACHU$ETTS onucn Application filed nayea sas, seriaino; 280,551..

The invention relates to chucks for use in 'rindin machines or othermachine tools b c 7 when it 1s desired to operate uponwork having along borethat must be ground or other; wise machined.

one from each end of the bore. Using an ordinar chuck for this, purpose itis neceseary to spend considerable time in. setting up the work in the chuck for tliesecond operation, if the separately ground ends of the bore are to be iii-axial alinernent. The chuck of the invention isndesigne'd toeliininate this time wasting. setting p operation by-providinf means for swinging. thex workpiece through one hundred and eighty degrees while it is still held by. thechuck aws, thus to grind bothends of'the bore pursuant to asingle act of clamping the'workpiece.

The attainment of the above, therefore, is one objectcf the invention. Anotherobject of the invention is the provision, in a chuck of this character, of a double set'of clamping jaws so that the workpiece may beheld at both ends. A still further object of theinvention is the provision of interconnected actuatingineans for the several sets of jaws, so that they may. be operated from a single lever. Furtherobjects of the invention reside in the means for holding the element that swings into two positions, in the features of adjustment, and the specific details of construction, all of which will more fully' appear froin the following description of an lillustrative embodiment of the invention, taken in connection with the accompanying" explanatory drawings, in which i Fig. l is a frontelevation of a chuck constructed in accordance with the invention,-

front endof the spindle. v r V Fa'stened to the platel in any suitable man- Fig. 2 is a side elevation of the chuck after it has beenrotated ninety degrees on its axis froin the position in which". it isi shown in,

, Fig. 3 is a longitudinal sectionalview taken on the ine 33 of Fig, 1. j

elis a fragmentary isometric View of one hf the jaws of the front set.

5 is a view similar to Fig.4, of one of the rearj aws andits actuatingmechanism.

, Like reference characters refer to like parts throughout the drawing. r c

The ordinary internal grinding machine providesa rotatably mounted spindle, driven by any suitable. means, the work carrying chuck being inounted upon the front of said spindle. Referring first to EigsQ and 3, the

chuck of theinventionis adapted to be fastened to such spindle, and to that'end a basel plate lof said chuck provides a central axial hole 2 which is internally threaded as'a-L Sto permit its attachmei'it ner as by means of bolts 4, is an annular mein her 5 wlnc'h, as,bestshown inF gs. 1 and 2, provides a pa r of fQXWfiiCllYPlOJECtHIgPOI- tions 6,6 which constitute supports for the rotatable mounting upon an axis perpendicu lar to the main axis of rotation, of the work clamping body which actually holds the workpiece. The work clamping-body colnprises an annularfraine portion'i, in which are carried the several sets of'jaws and actuating means therefor that will be described in. detail hereinafter, said body 7 providing trunnions 8, 8 which are received in bearings formed partly in the forwardly extending portions 6, 6, and partly in bearing caps 9, 9 that'are suitably fastened thereto as by means of screws 10. f

As has already been indicated the axis of support of the work holding body 7 is perpendicular to ,the axis of rotation of the chuck as a whole which is, of course, determined by theaxis of rotation of the, chuck carrying spindle. It follows from the above that the two axes are locate'dzin a given plane. 7 It is essential, not only that the foresees sadn ss be eeled bu e-et n to the 1 threaded journalling of the work carrying body 7 in the chuck be free from lost motion or bearing play. The above conditions being given, it

will be evident that if a cylindrical or conical workpiece, or' a'workpiece having any sur face of rcvolution, is so located 1n the work carrying body 7 that lts axis (that is-tosay the axis of the, workpiece) exactly-coincides all three axes have a single point in common,

I with. the axis of rotation of the chuck, and; the work carrying body 7 is then rotated through 180, the said axis of the workpiece will be found to again coincide with the'axis.

of rotation of the chuck. This is so because and thus no lateral displacement of the axis of the workpiece s possible, While turmngthere of through 180 will leave itwith the same angular relationship to every other line that provided. 7

pair of forwardly extending arms 11, 11. These arms 11, 1,1 are substantially diametri cally opposed to each other on the chuck member 5, and serve for the'supportof lock- .j

7 treme positions.

ing devices to hold the: body 7 in its twoex- 7 These locking devices pref erably take the form of plungers 12, 12, which have beveled'ends 13,13 constituting latches, and which are surrounded by springs 14:, 14.

the plungers being reduced in diameter as shown at 15, 15 to receive the springs. The latterserve to press the latches 13, 13: outward'ly into the path of co-operating means provided by the partially rotatable work holding body 7, while knobs16, 16 are provided by; the plungers, in order that the latches 13, 13 may be withdrawn from. the path ofsaidco-operatingmeans. 7 Y I I Carried by the work holdingbody 7, and preferably spaced angularly on" it substantially 90 from each of the trunnions 8, 8, is a rectangular blockl'i. This block constitutes the means thatco-operates with the latches 13, 13 to hold the body in its two opposed po-' sitions, and it also constitutesfan abutment to accurately-locate the body 7 in these posi tions. For the latter purpose a pair of co-opcrating stopslS, 18 are provided by the annular member 5. As shown in Figs, land 2, these stops .18, .18 are located adjacent the forwardly projecting arms 11, 11, and desirably take the form of screws or bolts in order that they shall be adjustable. Nuts19,

19 are provided to secure thebolts or stops 18,18 in the proper adjusted positions.

The fla-tsides of the block 17', when passing As best shown in Figs. 1 and 2, the annular supportingmembero of the chuck prov1des a screw 27, a pin 28 passing through said either one of the latches 13 force the same against the pressure of the corresponding spring ll, since the frontfaces of said latches have a gradual bevel relative to the aforesaid flatsurface's of the blocln as shown. lVhen,

however, the then front face of theblock 17; has passed beyond the tip of a particular latch 13, the back beveled edge of the latch is forced bythe springlt against this front surface, and the. angular relationship of these surfaces is such that the block 17 is pressed firmly against the stop 18 and cannot move therefrom, until the plunger is moved as by means of its knob-T16. In order to balance the work holding body 7, a counterweight 20 is provided thereby opposite the block 17. 1 I

For the securing and releasing of work pieces in the work holding body 7 in accurate alineinent with' the axis'of the chuck as a whole, the invention provides a double set of holding jaws, one ateach endof' said body, 1n order that the workpiece itself may be fir nly held and not deformed under the grinding pressure. As-illustrative of the utilityiof'the'chuck the "workpiece ashown in dotted. lines in F 1g; 3 "isa cluster gear, cast orforged in a single piece, the bore of which must beg-round concentrically with the pitch line of the several gear portions, the'workpiece being consequently gripped by means of a pair of these gear portions. Referring nowtoFigs. 3 and 4,,the work holding body 7 provides an internal cylindrical bore in which. isslidablyrnounted a. sleeve 21. A plurality'of jaw pieces 22 (desirably three in number as'is' the usual practice in chucks) are detachably fastened to sliding blocks 23 that are located in guides 24 provided in recesses 25formedfin the internal periphery of one end of the body 7, flat. springs 26 pressing the l sliding members 23 against the guides. The flat springs 26constitute links as well as spring means and atone end are fastened to the sleeve 21, as by means of a sleeve,and a fiatplate 29 provided to more securely hold the fiat springs; a clearance space 3 0 being provided on either side of the flat springs 26 near the front of the sleeve 21,

.to perm t fleXure of said springs.

At. the other'end the' flat springs26 are connectedto the slidable members 23, and in order to allow for the inward movement of these jaw holding members, the connection is a pivotedone. For that purpose, the front ends of'the springs 26 fit in rectangular slots defined by projecting portions 31, 31 provided by the members23, andare fastened to sl'abbed' off p'ortions'of cylindrical ,mem- I hers 32 which fit'in bearing holes 33 provided by the sides of the projections 31. The springs '26 are fastened to the members '32 bymeans of rivets 34,the heads of which extendinto cylindrical holes 35. Forthe initial grinding of' the jaws 22to'make'them concentricto the axis of the chuck the slidin members 23 can be held rigid to, the work holdin body 7, as by means ofscrews 36 shown in-Fig. 3, which are adapted tof'be screwed into tapped holes 37 provided the members 23. j

From the foregoing it chuck to the position shown in Fig; 3, the

slidable members 23 will be'drawn intosaid 1 chuck, and the jaws22 consequently'forced towards each other ina radial'direction, wing to the inclined surfaces on the guides 24. The sleeve21 is urge din this direction by means of a plurality of springs 38 fitting in holes 39 drilled in the body 7, .the outer ends of said springs pressing against seg ments 40 which are suitablylfastened to the sleeve 21. Beforedescribingthemeans provided by the chuck to move said. sleeve 21 againstthe pressure of the springs 38, the work holding jaws and actuating means therefor in the opposite endjfof the chuck will be described.

In a general way, the second set of jaws and actuating mechanism therefor embodies the same principles as those alreadydecribed, but it should be noted at the. outset that the inclined wedge means are inclined] in thesame direction in order that agiven actuation of 'the parts mayresult in' opening all the aws or closing all "the' jawa-as the case may be. Referring now to FigsB and" 5, a secondsleeve 41 is providedby the-body 'Zpbeing mountedin'side the-sleeve' 21 and fitting slidably' therein. "Both sleevespr'o vide three slots at their left=hand ends; as viewed in Fig. 3, in order'to'allowthree guide members 42 to befa'stened to th bod tions 51 constitute thesides of the guiding holes provided by inwardly extending portions 51 of the guide members 42. These pormeans for the jaw holding members "43, there bemg a pair of such portions provided by each guide member42, and consequently the chuck'may, and desirably does provide six of the-springs 49 which are located in the norti'ons 51' and press against the ring 45. The ring provides slots or clearance spaces 52, as shown in Fig. 5, in orderthatit may be movedtowards theyportions 51 when it is desired to open the chuck ]2].WS.

The ring 45 provides further slots 53 at will be obvious that when the sleeve 21 is urged rearwardly of the 't-hefbottom which are fastened," as by screws 5.4-and pins 55, flatsprings 56*which,

as in the caselof the fiat springs [26, con

stitute 1 means'not only to press the slidable members 43 against the guides 42, but act as links to draw them-rearwardly of the 'chuc'k, or'to press them forwardly in" response to the actuationof the 'ring45. The link springs '56 are-fastened at thej'other' end to the members 43 in exactly thesame manner asthe links26 wereffastened to the slidablemembers-23, this means comprising cylindrical members .57, rivets '58,1and' cylindrical 'holes' 59, together with bearingholes 60 to rotatably hold thecylindrical members. The slidable members 43 provide: radial inwardly extending portionstll, 61 to which are. fastened, as by means of s'crews '62, the jawipieces 44.

S lidably mounted in the hollow work 115,- tating spindle, that holds the chuck'of the.

invention, is a hollow shaft 63 that at once servesfor the conveying of coolant to the workpiecea being'ground, and as a means or opening and closing the chuck. When the work holding body 7 is in theposition, shown. in Fig- 8,.torward movement ofthe rod63j 'resultsin opening'the several, sets of jaws,

'by theiimpingement'of acu shaped memher 64 against the *ring 45., bitch movement 7 results in forward movement first'ef the ring 45,- and therefore-l the. sliding member's-'43, I

and-jaws 44, followed by forward movement ofth e-j aw pieces .22 as soo n' asthe flanges "4 7 f4'0,'the sleeve 21, and consequently-the ifla't springs 26.I1" It will be apparent'that the rear set of, jaws 44 will be openedfirst, and

in the subsequent closing of methane-u on la"workpiece dwhe n the push rod 68 is releasedfthey will be, therefore,- thelast to engage theworkpiece;j.

f WVhen usingthe chuck of the invention in a grinding or other machine, the operator fir'stpositions'the workholder body 7 in the I position. shown by Figs; 1, 2 and '3, so: that i the ring-"745. is just'in front of the annular edge ofthe cup shaped member Having .ma'desure that the corresponding latch '13 is in engagement with the front face of the blockl7, the operator moves the chuck operating' lever, not shown, provided by the main the spindlefcausing engagement of the operating member 64 with the ring 45, press ing this rin'g against the several springs 49 "and ultimately" pressing :the segments 40 against the springs 38; the sleeves 21 and '41 being thus'moved to'the right, Fig. 3, and the slidable members 23 and 48 being moved in the same direction to open both sets of jaws 22 and 44. V

The operator then places the workpiece a in the chuck and releases the chuck operating lever whereupon both sets of jaws 22 and 44 grip the workpiece and hold, it in centered 'have c'ontacted with and inoved'theseg'ments I chine which moves the shaft 63lr'orwardly as l P i n, r't Pr ne?' p d ngei-ah r gear-asnchas shown injFig. 3, rings 65 and 66 are provided, eachione of which loosely l holds three pins 67 and GSIrespectiVely,. the

said pins being: oi asiZe toifiti between the "teeth of the end gear portions substantially in engagement'with the pitchline iof said, gear portions. The jaws 22ancl factually engage these pins instead o f the gears themselves. 1

groundin the usual manner, and when this grinding operation is'finished the work'holding body 7 can .befr,otated or indexed 180 to bringtheblock 17 in engagement ,With'the opposite stop 18, and the borefc can then be ground, all without many way disturbing the setting and clamping. of the: workpiece atv in the body 7 Both bores 79 and 0 having thus been'ground concentric with the commonaxis of the pltch lmesof the and gear portions,

the work holding, body should. then be turned back to its original position as shown in Eigi'i i, andby operation of the chuc operating lever the cup shaped member can then be forced into engagement with the ring 45, whichagainlspreads the -jaws.22;

and 14, allowing thefinished workpiece to be f removed fromrthe -.machine and another one 7 I I l inserted in its place, Weclaim, I 1 i l 1.; Inapparatus of the class described, a

' V chucking member. adapted tofbe rotated through 180" to successively present "opposite ends of a workpiece therein to a cutting tool, 'a;set of work-clamping jawsat each-end ofsaid member, a. pair of sleeves, 7 one inside the othereconnected .to said several sets ot jaws, aj lost-motionconncetlon between said sleeves, and wedge; means to cause the jaws to open or close upon movement of said sleeves in a given direction,- whereby by the use of a single operating member said jaws maybe simultaneously opened enclosed, one

set of awsmoving before the other, set by reason of said lostmotion connection.

:2 In achuck, a workholding. body, a base adapted to, be attacheldto a spindle, a pivotal mounting for said workholding body in said base, the pivotal axis being perpendicular to the axis of rotation'of the; spindleand base,

a set of slidable jaws in said workholding body adapted toholda workpiece therein when moved generally parallel: to ethe lnain axis of the chuck, a jaw actuating member, and a longitudinally movable member passsition. 7 V i- V 3. In a'chuck, abase'adapted to be attached to a spindle for rotationabout an axis, a workholding body pivotally mounted in said b se. on a ax nerpe eul r "to e; a is 9 ing into the vbase normally separate from' the jaw-actuatingmember but adapted to be urged into engagement with it to actuate said j aws when the Workholdin g body-is in one porotation of said base, saidworkholdingbody comprising anannular member, a set of workholding jaws movable generally parallel to 1 theflgeometricahaxis of the v-w orkholding body, wedge means; cooperating. with said jaws to cause them to grip a workpiece when movedvin. one v direction, spring meansurging them in this direction, and a longitudinally movable member projecting 'through the base normally diconnected from :said jaws but adapted, when pushed forward, to cause the jawstofrelease a w'orkpieceL a Agfllna chuck, a base, adapted to be fastened; to a spindle and therefore to be revolved on an axis, aworkholding body: comprising an annular member mountedf or partial rota I c t on 1n said baseon a line perpendlcular to ithe axis 'of rotationjof said base and alsoto V spring means "associated said direction, and meansin said base normally totally-.,disconnected from Y-said jaw members but adapted tobe urged towards themwhenthechuckis in one extreme posi- "tionvof oscillationfto cause openingfof said jaws, for -the release of the workpiece."

I I In achuek, a base adapted to befastened V to spindle andvtherefore tOfbQ revolved on an -axis, aworkholding body comprising an r annular'member mounted-for partial rotatheaxis of rotation of; said base and also to itsown 'geometriciaxis,a set of jaw members at each end of said annular member, coopereating wedge meansat each end of said annular member "arranged to cause the jaw membersto move towardsthe center of the tion insaid baseon a line perpendicular to annularmember by a longitudinal movement ther'eo f,in"a given direction forall thejaw members, a pair ofconcentricsleeves, one insidelthe other, each sleeve having connections with-the separate'jaw members of aset, the two sleeves thus-controlling both sets of jaw members, spring meansin the annularmember, and longitudinally movablemeans in the chuekbase, the latter being normally discon- J1ected-from-the sleeves, and the last two meansserving to urge the'sleeves in one direction'toopen the chuck and in the-other direc- 1 tion toclose it.

6. In apparatus as claimed in claim two separate sets of spring means, one set for each sleeve, whereby to hold a workpiece at both endsofthe chuck with a separate adjustable action, the longitudinally movable meansbe- -ing adapted, in oneposit'ion of the annular memberto release all the jaws.

GEORGEE. GARNOQ EUGENE A. ENGSTROM. 

